The goal of this project is to develop an efficient technique for the production of high specific activity copper-64 with small biomedical accelerators. Copper-64 (t 1/2 = 12.7 hr.) is an intermediate half-life positron emitting radionuclide which has been shown to be a useful radiotracer for positron emission tomography (PET) as well as a promising radiotherapy agent for the treatment of colorectal cancer. Copper-64 is currently reactor-produced and, because this radionuclide can only be produced at a small number of reactor facilities, its availability is extremely limited. We propose to develop an innovative radioisotope target and separation system which will allow the production of clinically useful quantities of copper-64 with conventional PET cyclotrons as well as with the low energy linear accelerators which have recently become available for PET. Copper-64 will be produced by the 64Ni(p,n) reaction. In Phase I, the optimum target irradiation conditions will be determined, and techniques will be developed for the separation and purification of high specific activity copper-64 and for recovery of the nickel-64 target material. These studies will lead to the design of a self-contained, automated system for the accelerator production and purification of copper-64 in the quantities required for imaging and radiotherapy. PROPOSED COMMERCIAL APPLICATION: The copper-64 production system developed in this program would be of immediate use to researchers having access to hospital-based cyclotrons and to existing radiopharmacy-based accelerator facilities. The availability of a convenient system for the on-site, on-demand production of copper-64 will facilitate the further development of imaging and radiotherapy protocols using copper-labeled compounds.